This study is to clarify the results of atrial septal defect(ASD) repair and mitral valve surgery through right anterolateral thoracotomy since 1989, and those of more generalized application of minimal invasive cardiac surgery since August 1997. We retrospectively analyzed the results of open heart surgery(OHS) through other than full sternotomy carried out until October 1997. There were 28 cases of OHS done through right anterolateral thoracotomy(17 cases of ASD, 4 cases of mitral valve repair, 6 cases of mitral valve replacement, and 1 redo mitral and tricuspid valve repalcement) which has demonstrated no surgical mortality or morbidity except only 1 case of reoperation for bleeding. During the period between August and October 1997, we performed near routine application of upper sternotomy or transverse sternotomy in aortic valve cases and routine application of minimal incision in cases with ASD and there was no evidence of early and late complications associated with this approach. We conclude that OHS with the use of minimal incisions is very safe, cosmetically excellent, and superior in terms of the amount of bleeding. The indication for minimal incision, therefore, should be extended afterwards.